Opera, Operetta and Musical Theater scores are available by individual work, composer or compilation (excerpts).
Browsing the Library Shelves for Scores
Check call numbers ML 1500 through ML 1508, which are located on the second floor of the Music Library. Specifically:
||Full Scores--Operas and Musicals
||Vocal/Piano Scores--Operas and Musicals
||Operettas and Musical Revues
Browsing the Library Catalog for Scores
In the catalog, use Subject Headings, Title, or Author (lastname, firstname) to browse scores. The following is a non-exhaustive list of subject headings that can guide your libretti searches. (For a full list follow the link above.)